The present invention relates to an apparatus for controlling the combustion in a heater, and more particularly to an apparatus for controlling the combustion in a heater to control the condition in which fuel is combusted in the heater.
The passenger compartment or cabin of a vehicle is heated by supplying the compartment with hot air heated by cooling water of the internal combustion engine of the vehicle. However, in cold weather, it takes time to increase the temperature of the cooling water, and hence the compartment cannot be heated quickly.
Japanese Laid-Open Patent Publication No. 61-157422 discloses a proposed vehicle heater device in which fuel is combusted by a burner separate from the internal combustion engine and heat generated by the fuel combustion is recovered by a heat exchanger to supply heating air into the compartment, the burner being controlled dependent on the operating condition of the engine. In the disclosed vehicle heater device, a controller including a bridge circuit and a comparator is employed to control supplied electric power to keep the temperatures of an atomizing glow plug and an igniting glow plug in the burner at respective predetermined temperature levels.
According to the aforementioned vehicle heater device, the temperatures of the atomizing and igniting glow plugs are controlled at the respective temperature levels, as described above. In the event that operation of the burner is interrupted due to an engine failure or the like and the burner is to be ignited again, only a basic re-ignition mode is used without concern over different ignition performances of fuels. Where the temperature in the burner is low or a low-quality fuel is used, the fuel cannot be re-ignited, and the combustion remains interrupted.